EVANSTON, Ill. --- Scientists in the Auditory Neuroscience Laboratory at Northwestern University have developed a new diagnostic tool that can quickly and objectively identify disordered auditory processing of sound, a problem associated with learning impairments in many children. With early detection, these children have a high likelihood of benefiting from remediation strategies involving auditory training. The University recently licensed the technology, called BioMAP (Biological Marker of Auditory Processing), to Bio-logic Systems Corp., located in Mundelein, Ill. "The original versions of BioMAP have been used to demonstrate that brainstem-level neural timing deficits exist in roughly 30 percent of children with language-based learning problems such as dyslexia and in children whose speech perception is extraordinarily disrupted by environmental noise," said Nina Kraus, Hugh Knowles Professor and director of the Auditory Neuroscience Laboratory. "In our experience, children with these timing deficits appear to benefit most from remediation strategies involving computer-based auditory training. We anticipate that our partnership with Bio-logic will be fruitful in making this objective marker of auditory function available to clinics and private practices worldwide."

Keyword: Hearing
Link ID: 6829 - Posted: 02.08.2005

Smoking marijuana can affect blood flow in the brain so much that it takes over a month to return to normal. And for heavy smokers, the effects could last much longer, a new study suggests. Regular marijuana use can harm memory and the ability to make decisions, according to Jean Cadet at the National Institute on Drug Abuse in Baltimore, Maryland, US. To find out why, he monitored the flow of blood through the brains of 54 marijuana smokers, among whom the heaviest user smoked 50 joints every day. People who smoked cannabis had higher blood flow through their brains than non-users. Yet there was also greater resistance to the blood flow, suggesting that cannabis changes the blood vessels in the brain in a way which hinders oxygen in reaching the tissue effectively. In an attempt to compensate, extra blood is sent to that part of the brain, increasing resistance but probably failing to get enough oxygen through the vessels, Cadet suggests. Cadet and his colleagues used an extremely sensitive non-invasive technique called transcranial Doppler sonography to "see" the blood flow through individual arteries from the head's surface. After a month without cannabis - during which the volunteers agreed to remain in a clinic, with no access to marijuana - Cadet repeated the sonography. The resistance to blood flow of light and moderate users - who usually smoked an average of 11 and 44 joints per week, respectively - was starting to return to normal. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse; Learning & Memory
Link ID: 6828 - Posted: 06.24.2010

Emma Marris For almost half a century, a population of foxes in Siberia has been bred to be unafraid of humans and non-aggressive. Now these foxes seem to have shown that social skills come as a perk of being friendly. Dogs, domesticated from their wild wolf cousins over millennia, are not only less likely to bite or bolt, but have also gained the ability to communicate with their human companions. For example, if a human points or looks at an object, the dog will also look at it. Brian Hare, an anthropologist at Harvard University in Cambridge, Massachusetts, had previously shown that dogs are more likely than undomesticated animals - even chimps - to be able to communicate in this way with humans. But was this social sophistication something that was specifically bred for during their domestication, or was it a by-product? An opportunity to find out came from the Siberian foxes, which have been bred for friendliness but have had limited contact with humans. The project was set up in 1959 by Dmitry K. Belyaev of the Institute of Cytology and Genetics in Novosibirsk to examine the genetics of domestication. Each fox is tested at the age of seven months to see whether they approach humans (and whether they bite). The 'friendlier' foxes are bred, and a separate, control, population is bred randomly. ©2005 Nature Publishing Group

Keyword: Intelligence; Evolution
Link ID: 6827 - Posted: 06.24.2010

By Joanna Downer, Johns Hopkins Medicine In experiments with rats, Johns Hopkins researchers have discovered that the shut-off switch for the auditory system is quite similar to an "on" switch previously known principally in muscle. The findings appear in the Dec. 8 issue of the Journal of Neuroscience. Calcium was already known to be a key factor in both systems. It helps trigger contraction of muscles, and it helps the brain rapidly shut down the ear's sound-detecting "hair cells," named for the spiky projections that help translate sound waves into electricity. However, the amount of calcium coming into hair cells in response to the brain's signals has always seemed too small to do the trick. Now, the Hopkins researchers report that the small influx of calcium triggered by the "shut-off" nerve causes a flood of calcium to be released from a reservoir sitting just inside the hair cell. That flood, in turn, quiets the hair cell by stimulating its release of potassium. "We've known the response to the nerve is practically immediate, and people had suggested that perhaps the cells had a reservoir of calcium that made it possible," said Paul Fuchs, professor of otolaryngology — head and neck surgery, of neuroscience and of biomedical engineering and director of the Cochlear Neurotransmission Laboratory at the Center for Hearing and Balance at Johns Hopkins. "Our evidence strongly supports this idea and shows how it happens. The similarities to the situation in muscle is striking."

Keyword: Hearing
Link ID: 6826 - Posted: 06.24.2010

By JEREMY PEARCE Dr. Peter E. Stokes, a Cornell endocrinologist and psychiatrist and a pioneer in the use of lithium to treat manic depression, died on Jan. 22 at St. Luke's-Roosevelt Hospital Center in Manhattan. He was 78. He had been hospitalized since November, and a cause of death was not determined, his family said. Dr. Stokes, who taught for four decades at Cornell, qualified first in endocrinology before training in psychiatry during the 1960's. After early research in anxiety, through the field of neuroendocrinology, he turned to the study of depression. In 1965, at the Payne Whitney Clinic in Manhattan, he and other scientists began to investigate the effects of lithium, in the form of a salt, in controlling bipolar disease and manic depression. The encouraging results of the study were published in The Lancet, a British medical journal, in 1971. Lithium was approved for use in the United States in 1970. Dr. Jack D. Barchas, chairman of Cornell's department of psychiatry, said Dr. Stokes's studies had been "very important in working out lithium dosages and the best treatment regimes." Copyright 2005 The New York Times Company

Keyword: Schizophrenia; Depression
Link ID: 6825 - Posted: 02.07.2005

By Elizabeth Williamson By most physical measures, teenagers should be the world's best drivers. Their muscles are supple, their reflexes quick, their senses at a lifetime peak. Yet car crashes kill more of them than any other cause -- a problem, some researchers believe, that is rooted in the adolescent brain. A National Institutes of Health study suggests that the region of the brain that inhibits risky behavior is not fully formed until age 25, a finding with implications for a host of policies, including the nation's driving laws. "We'd thought the highest levels of physical and brain maturity were reached by age 18, maybe earlier -- so this threw us," said Jay Giedd, a pediatric psychiatrist leading the study, which released its first results in April. That makes adolescence "a dangerous time, when it should be the best." Last month, Sen. William C. Mims (R-Loudoun) cited brain development research in proposing a Virginia bill that would ban cell phone use in vehicles by drivers younger than 18. It passed Friday. © 2005 The Washington Post Company

Keyword: Development of the Brain
Link ID: 6824 - Posted: 06.24.2010

PHILADELPHIA, PA -- Variation in a taste receptor gene influences taste sensitivity of children and adults, accounting for individual differences in taste preferences and food selection, report a team of researchers from the Monell Chemical Senses Center. In addition to genes, age and culture also contribute to taste preferences, at times overriding the influence of genetics. The findings may help to explain why some children are more attracted to sweet-tasting foods, as well as why taste and food preferences appear to change with age. "The sense of taste is an important determinant of what children eat. We know that young children eat what they like. We also know that many children do not like bitter taste, thereby interfering with vegetable consumption and potentially limiting intake of important nutrients," comments lead author Julie Mennella, PhD, a developmental psychobiologist. "The recent Nobel Prize award demonstrates the importance of the identification of genes coding for taste and olfactory receptors. We took advantage of this new knowledge to look at how variation in taste genes might relate to the taste likes and dislikes of children and parents." In the study, to be published in the February 2005 issue of Pediatrics, researchers compared taste sensitivity and food-related behaviors across three genotypes of the TAS2R38 gene, which encodes a taste receptor responsive to bitter taste.

Keyword: Chemical Senses (Smell & Taste); Genes & Behavior
Link ID: 6823 - Posted: 02.07.2005

BACKGROUND: Alcohol interferes with how brain cells communicate with one another, coordination, grogginess, impaired memory and loss of inhibitions associated with drunkenness. Yet researchers have been unable to pinpoint how alcohol causes this disruption in the brain. FINDINGS: Now scientists at the David Geffen School of Medicine at UCLA have deciphered how a naturally occurring gene mutation in rats' brains lowers the animals' tolerance to alcohol, leading to rapid and acute intoxication after the equivalent of one drink. The UCLA study is the first to identify how the gene variation alters GABA receptors -- specific sites targeted by chemicals from the brain cells -- making them more responsive to very low levels of alcohol. Alcohol enhances the GABA receptors' influence on brain cells, slowing the cells' activity and ability to communicate. IMPACT: The fact that the gene mutation arises naturally suggests that tolerance levels to alcohol may be genetically wired in people, too. If so, the findings could eventually help identify children and adults at higher risk of developing alcohol dependency, so these individuals can make an informed decision about whether to drink. The study results may also speed the development of new drugs that target alcohol-sensitive GABA receptors, leading to better treatments for alcohol poisoning and addiction.

Keyword: Drug Abuse; Genes & Behavior
Link ID: 6822 - Posted: 02.07.2005

WASHINGTON — Underscoring the value of good prenatal care, new research suggests that early infection may create a cognitive vulnerability that appears later during stress on the immune system. Researchers at the University of Colorado at Boulder have reported that rats who experienced a one-time infection as newborns didn’t learn as well as adult rats who were not infected as pups, after their immunity was challenged. The research is in February’s Behavioral Neuroscience, published by the American Psychological Association (APA). The findings fit into a growing body of evidence that even a one-time infection can potentially permanently change physiological systems, a phenomenon called “perinatal programming.” Understanding how infection in newborns can disrupt memory in immune-challenged adults may help scientists to understand how exposure to germs or environmental stressors before or just after birth may foster susceptibility to neuropsychiatric and neurodegenerative diseases. For example, prenatal viral infection has been implicated in schizophrenia, autism and cerebral palsy; bacterial infection is a risk factor for Parkinson’s disease. Up to 20 percent of pregnancies have complications involving infections of the uterus and its contents, a number that will rise as more children are born premature. © 2005 American Psychological Association

Keyword: Neuroimmunology; Learning & Memory
Link ID: 6821 - Posted: 06.24.2010

Stroke survivors who stop taking their daily prescription of aspirin triple the risk of another stroke within a month, research suggests. Aspirin has been shown to cut the risk of recurrent stroke by about 25%. But Swiss research suggests the protective effect is rapidly lost when aspirin is no longer taken. If confirmed, the findings may prompt a rethink of the current advice that patients stop taking aspirin in the days before undergoing minor surgery. Each year in England and Wales, more than 130,000 people have a stroke and, of these, more than 53,000 are recurrent strokes. The researchers say their work underlines the importance of complying with therapy. The Swiss researchers focused on 309 patients who had a stroke or a mini-stroke - known as a transient ischemic attack (TIA) - and later went on to suffer a further episode. All of this group had at least inititally been put on long-term aspirin therapy. The researchers said they found that in 13 cases the patients had stopped taking their aspirin in the four weeks leading up to their latest stroke. To find out how significant this was, the researchers found another group of 309 stroke patients, who had also been prescribed aspirin but this time had not suffered a recurrent stroke. In this group, just four patients admitted they had stopped taking their pills during the four weeks surveyed. From this the researchers, who presented their findings at a conference of the American Stroke Association, calculated that stopping aspirin therapy increased the short term risk of a recurrent stroke by more than three times. However, they admit more work is needed to firm up their conclusions. (C)BBC

Keyword: Stroke
Link ID: 6820 - Posted: 02.05.2005

Two-time Super Bowl linebacker Lionel Aldridge hallucinates himself into homelessness. The famous Russian dancer Vaslov Nijinsky swaps the stage for an institution. Nobel Prize winning mathematician John Nash hears strange voices that bring his work to a near halt. Miles and professions apart, these men have or had one thing in common: all were all ensnared in worlds where the fear and disordered thought that accompanies schizophrenia permanently altered their lives. Much is still unknown about the disease but for the first time scientists have identified a fault in schizophrenics' brain waves at a frequency called the gamma range—it cycles at between 30 to 100 brain waves per second—where healthy brains piece together perceptions. "We think this means that [schizophrenics] have a decreased deficiency of communication in between brain areas," says Robert McCarley, chair of the Harvard psychiatry department and chief of staff for mental health services at the VA Boston Healthcare System. "We see gamma as evidence that the brain is putting together all of these individual sensations to make a single perception. None of the other brain frequencies are involved in this process." McCarley, along with neuroscientist Kevin Spencer, also of the VA Boston Healthcare System and Harvard University, believe that this disturbance could explain what's behind particular symptoms in schizophrenics, including disordered thought and hallucinations. To look more closely at how gamma works in the brain, McCarley and Spencer used electroenchephalography (EEG) recordings that measure the electrical communication between nerve cells. Existing research had already shown that identifying a square shape elicited signals picked up in the gamma range, so the two recorded brain waves in twenty male schizophrenics and twenty healthy males, matched for age, education and parents' social status, as the groups were shown images and asked to press a button when they thought they saw a square. © ScienCentral, 2000- 2005.

Keyword: Schizophrenia
Link ID: 6819 - Posted: 06.24.2010

Biologists at Lehigh University and the University of Maryland have identified a cricket living in Hawaii's forests as the world's fastest-evolving invertebrate. Finicky mating behavior appears to be the driving force behind the speedy speciation of the Laupala cricket, the scientists wrote in the Jan. 27 issue of Nature magazine. Females in the Laupala genus detect tiny differences in the pulse rates of male courtship songs, which differ from one Laupala species to the next. They refuse to mate with males of other species, thus promoting the formation of new species. The scientists say their findings shed light on the role of individual choices in the evolution of species and the growth of biodiversity. "Animals with nervous systems and brains have preferences and can make choices," says Tamra Mendelson, an evolutionary biologist at Lehigh. "Changes in these preferences and choices appear to drive speciation. "That raises the question: Can something seemingly so individual as a choice have macro-evolutionary consequences in terms of increasing biodiversity? If so, this affects how life on the planet looks. The more species you have, the more complex the ecology is going to be."

Keyword: Sexual Behavior; Evolution
Link ID: 6818 - Posted: 02.05.2005

David Shiga Doctors could soon have a definitive diagnostic test for Alzheimer's disease, thanks to some tiny but sophisticated sensors. These nanoscale particles isolate extremely small quantities of protein clumps associated with the neurodegenerative disease. The researchers tested cerebrospinal fluid, which bathes the spinal cord and parts of the brain. They took samples from 15 people confirmed after death to have had the brain plaques characteristic of Alzheimer's disease and from 15 people who were free of the disease. The samples were collected from living people as well as from individuals who had died. With two exceptions, patients who might have been misdiagnosed, the nanoparticle test distinguished the two groups by detecting the prevalence of protein clumps called amyloid beta–diffusible ligands (ADDLs) in the Alzheimer's patients, the researchers say. ADDLs are "invisible to conventional neuropathology, but their presence or absence may be the real determinants of memory loss," says team member William L. Klein of Northwestern University in Evanston, Ill. For the test, Dimitra G. Georganopoulou, also of Northwestern, and her colleagues used iron particles coated with antibodies that stick to ADDLs. They mixed the iron particles into each sample and later used a magnetic field to extract them. The particles dragged along any ADDLs in the sample. Copyright ©2005 Science Service.

Keyword: Alzheimers
Link ID: 6817 - Posted: 06.24.2010

COLUMBUS, Ohio – A new study suggests that people with autism may perform unusually well on some tests of visual processing. The researchers found that autistic people were less likely than others to have false memories about images they had seen earlier. The researchers had previously demonstrated this kind of effect with verbal material, but not with visual material. In this case, the results suggest that the autistic people had trouble seeing the images in context – a hallmark of the disorder. The study's findings point out that the effects of autism may be more general than researchers once thought. "We thought that the effects of autism might go beyond language problems – that it affects different areas of the brain," said David Beversdorf, a study co-author and an assistant professor of neurology at Ohio State University. In 2000, he led a similar study that looked at the effect of autism on language. "We wanted to see if we'd get similar results with a visual model, and we did." Beversdorf and his colleagues presented their findings on February 4 in St. Louis at the annual meeting of the International Neuropsychological Society. The researchers tested a total of 28 adults, 14 of whom were high-functioning autistics – these participants could verbalize their thoughts (people with severe forms of autism often can't or don't speak.)

Keyword: Autism
Link ID: 6816 - Posted: 06.24.2010

RESTON, Va.--Scientists have demonstrated a new way to assess the potentially damaging effects of prenatal drug exposure--a technique that could also be used to monitor a fetus's response to therapeutic drugs--using sophisticated, noninvasive medical imaging tools. Scientists at the U.S. Department of Energy's Brookhaven National Laboratory, whose findings are reported in the February issue of the Society of Nuclear Medicine's Journal of Nuclear Medicine, used positron emission tomography (PET) combined with magnetic resonance imaging (MRI) to track the uptake and distribution of trace amounts of cocaine in pregnant monkeys and found significant differences in where and how fast the drug accumulates in maternal and fetal organs. "Understanding how drugs are transferred between a mother and her fetus during pregnancy may help us unravel the mechanisms of the drug's damaging effects on unborn children," said SNM member Helene Benveniste, M.D., Ph.D., chair of Brookhaven's medical department in Upton, N.Y., and lead author of the paper, "Maternal and Fetal 11C-Cocaine Uptake and Kinetics Measured In Vivo by Combined PET and MRI in Pregnant Nonhuman Primates." "While studies that follow human drug abusers and their children over decades provide valuable information, animal studies can more quickly provide clues to the underlying mechanisms of damage and suggest ways to test new treatment or prevention strategies," said Benveniste.

Keyword: Drug Abuse; Development of the Brain
Link ID: 6815 - Posted: 02.05.2005

Michael Hopkin The evolutionary biologist Ernst Mayr died on 3 February at the age of 100, after a short illness. A hugely prolific writer and researcher, he was instrumental in developing modern ideas in evolutionary theory. As an ornithologist, Mayr classified many birds, most notably risking the hostile terrain of New Guinea to catalogue the region's birds of paradise. But he will arguably be best remembered for formulating the concept of species that students still use today. It was Mayr who defined a species as a group of individuals that are capable of breeding with one another, but not with others outside the group. This led to the idea that new species can arise when an existing species becomes separated into two populations that gradually become too distinct to interbreed; it was an answer to a biological conundrum that had eluded Charles Darwin. Born in Bavaria, Germany, on 5 July 1904, the young Mayr was fascinated with wildlife but, at 20, was set to enter the medical profession. When offered the chance to visit the tropics to study birds, he completed a PhD in just 16 months before taking up a position at the Berlin Museum in 1926, from which sprang his work in New Guinea. ©2005 Nature Publishing Group

Keyword: Evolution
Link ID: 6814 - Posted: 06.24.2010

Roxanne Khamsi As people grow older, their vision can actually get better in some ways, according to a Canadian study. The findings suggest that neurological changes could help the elderly to spot small motions in otherwise uniform scenes. Part of visual processing in the human brain involves cells that suppress each other's activity. This allows the mind to focus on a scene's important features while ignoring trivial regions. But as people age, these inhibitory interactions seem to weaken. To explore the effects of this change, researchers tested people between 18 and 31 years old, and others aged 60 and above. Subjects viewed a computer screen showing moving, vertical black-and-white stripes. They then had to decide in which direction the bands were travelling. Previous studies have shown that, as the number of stripes in view increases, young people become much worse at identifying their movement. Scientists think that the stripes' large, stark borders activate the brains inhibitory mechanisms. The mind starts disregarding these monotonous forms. ©2005 Nature Publishing Group

Keyword: Vision
Link ID: 6813 - Posted: 06.24.2010

Katherine Seligman, Chronicle Staff Writer California's mysterious explosion of autism cases worsened in 2004, disappointing researchers who had hoped the number of new diagnoses would level off as they searched for an explanation for the neurological disorder. The number of people treated for autism at regional centers operated by the state Department of Developmental Services increased 13 percent last year from 2003, according to agency figures. Autism now accounts for a little more than half of the new cases handled at the centers, which treat a variety of developmental problems. An average of nine new autism cases a day come to the state's attention, the vast majority in children 13 and younger. Scientists have various theories, but there is little agreement about what is driving the growth of autism cases in California. The number of autistic people getting services at the centers has increased from 5,000 in 1993 to more than 26,000 now. "I'm really worried," said Jim Burton, head of the state-funded Regional Center for the East Bay, which provides treatment referrals and services for people with autism. "The burden is huge, and it's going to strain all our resources." ©2005 San Francisco Chronicle

Keyword: Autism
Link ID: 6812 - Posted: 06.24.2010

By BARNABY J. FEDER The Food and Drug Administration said yesterday that it might permit an implantable electrical device for the treatment of epilepsy made by Cyberonics to also be marketed as a therapy for chronic depression that is resistant to other treatments. The agency set a number of conditions on the tentative approval, and Cyberonics said it hoped to meet them before the end of May. Cyberonics, based in Houston, said 4.4 million Americans suffer the severe and recurring forms of depression that might be treated with the $15,000 device, more than 10 times the number who might use it to reduce or eliminate epileptic seizures. "If it is adopted for depression at the same rate as it has been for epilepsy, we will pass $1 billion in sales by 2010," said Robert P. Cummins, the chairman, chief executive and president of the company. Shares of Cyberonics rose $11.53, or nearly 42 percent, to $39.01 in heavy trading. Cyberonics lost $4.93 million on sales of $50.57 million in the first half of the current fiscal year, which ends in April. Copyright 2005 The New York Times Company

Keyword: Depression
Link ID: 6811 - Posted: 02.04.2005

By BENEDICT CAREY In the wake of a yearlong debate over the risks of antidepressants to minors, an analysis of World Health Organization medical records has found that infants whose mothers took the drugs while pregnant may suffer withdrawal symptoms. The study challenges the assurances that many doctors have long given pregnant women with depression that taking the drugs would not affect their babies. But experts said that the study, appearing today in the journal Lancet, was not definitive and must be weighed against the benefits of drug treatment. Untreated maternal depression can also harm a developing fetus, the experts said, and may lead to lasting childhood problems; all of the infants in the study recovered completely from withdrawal symptoms within 24 hours. "This study is important in that it gives us a red flag that babies exposed to antidepressants during pregnancy should be closely observed, and may go through unusual behaviors at first," said Dr. Timothy Oberlander, a developmental pediatrician at the University of British Columbia. Dr. Oberlander was not involved in the research and does not conduct research or act as a consultant for pharmaceutical companies. Some 10 percent to 15 percent of women suffer bouts of depression during the hormonal chaos of pregnancy, and about a quarter of those women get antidepressant treatment, doctors estimate, usually with drugs like Prozac, Paxil and Zoloft. If not treated, these women may also be at increased risk of postpartum depression, a devastating disorder that not only clouds the relationship between mother and child but can also interfere with the child's social development, according to Dr. Janet DiPietro, a professor at the Johns Hopkins School of Public Health. Copyright 2005 The New York Times Company

Keyword: Depression; Development of the Brain
Link ID: 6810 - Posted: 02.04.2005